This invention relates to the processing of rice to produce dehydrated rice products, and more particularly, relates to the processing of rice to produce precooked and dehydrated rice products for use as precooked rice products. In a preferred embodiment of the invention produces a precooked and dehydrated rice product for use in dehydrated foods such as soups and other foods which require only the addition of boiling water to provide a cooked and palatable food.
Precooked and dehydrated foodstuffs for use in dehydrated food mixes preferrably require only the addition of a specified quantity of boiling water to both warm and reconstitute the foodstuff to a palatable, hydrated condition. Such foodstuffs do not require any additional cooking to render them ready to eat and are capable of being consumed within a few minutes after the addition of the boiling water.
Typically, dehydrated food mixes come in a package which serves to store the product and serves as a moisture barrier. For some ready-to-eat products the package may also serve as the eating container, after rehydration with boiling water. These food mixes have initially been confined to simple products having a relatively small number of constituents, such as soups, but now include many diverse and complex products, such as entire dinners.
Further, these food mixes have tended to include wheat products because wheat products do not require a complete wheat "grain" to be recognized as a foodstuff and are thereby easily included in non-grain processed forms that are coked and dehydrated. For example, soups may include cooked and dehydrated noodles that are very thin to allow for quick rehydration of the noodle. The desire to include whole grain rice products in these foodstuffs has led to the need for a precooked and dehydrated whole grain rice product compatible with other such precooked and dehydrated foodstuffs. However, such a whole grain rice product must have an appearance similar to conventionally cooked rice grains, as well as being comparable in taste, or palatability, texture, and stickiness.
Although the need for such a precooked and dehydrated rice product has been known for some time, the existing products and processes for producing these products have not been completely successful on a commercial basis. U.S. Pat. No. 4,333,960 to Barry et al discusses the shortcomings of some of the processes available in this area. In summary, Barry et al states that these prior processes are not commercially successful because they: (1) require additional cooking after the addition of boiling water, or (2) produce a ready to eat product not requiring rehydration, or (3) use an initial raw rice product that results in materials that are difficult, if not impossible, to handle on an economic and commercial scale.
U.S. Pat. No. 4,333,960 to Barry et al does not easily lend itself to an economical and continuous commercial process because of its initial "soaking" step. Further, as taught in this patent, the color of the product after the "puffing" step is very dependent upon the "puffing" temperature and the product is easily scorched or burned at the higher puffing temperatures taught in this patent.
Further the Barry et al process, and other prior art processes, are designed to prevent any bursting, or popping, of starch granules in the rice grain. This prevention of bursting is to minimize cooking losses, but such processes provide starch of reduced solubility in the starch granules, as compared with the solubility of starch outside the granules. However, increasing the solubility of starch substantially increases the rate of rehydration especially for expanded, or "puffed", rice grains, as compared to rice grains which have been expanded with intact starch granules.
These and other limitations and disadvantages of the prior art are overcome by the present invention, and improved methods and apparatus are provided for producing a cooked and dehydrated rice capable of rapid rehydration, using an economical and continuous commercial process.